J. Jansen, “The infield-outfield farming system as a major solution for sustainable management of the semi-natural and cultural heritage in Parque Natural da Serra da Estrela”, Lazaroa, vol. 29, pp. 19–26, Feb. 2009, Accessed: Dec. 05, 2025. Available: https://revistas.ucm.es/index.php/LAZA/article/view/LAZA0808110019A